514 POPULAR SCIENCE MONTHLY. ' 



broad domain of every-day life rather than from the special, though 

 rapidly widening, fields of scientific activity. 



Between this nominally unlimited freedom on the one hand, and 

 these actually narrow restrictions on the other, I have chosen to invite 

 your attention for the hour to a summary view of the salient features 

 of scientific progress, with special reference to its effects on the masses, 

 rather than on the individuals, of mankind. We all know, at least 

 in a general way, what such progress is. We are assured almost daily 

 by the public press and by popular consent that the present is not only 

 an age of scientific progress, but that it is preeminently the age of 

 scientific progress. And with respect to the future of scientific achieve- 

 ment, the consensus of expert opinion is cheerfully hopeful, and the 

 consensus of public opinion is extremely optimistic. Indeed, to borrow 

 the language sometimes used by the rulers of nations, it may be said 

 that the realm of science is now at peace with all foreign parts of the 

 world, and in a state of the happiest domestic prosperity. 



But times have not been always thus pleasant and promising for 

 science. As we look backward over the history of scientific progress 

 it is seen that our realm has been taxed often to the utmost in defense 

 of its autonomy, and that the present state of domestic felicity, border- 

 ing on tranquillity, has been preceded often by states of domestic dis- 

 cord bordering on dissolution. And, as we look forward into the new 

 century before us, we may well enquire whether science has vanquished 

 its foreign enemies and settled its domestic disputes for good and all, or 

 whether future conquests can be made only by a similarly wasteful out- 

 lay of energy to that which has accompanied the advances of the past. 

 Especially may we fitly enquire on an occasion like the present what are 

 the types of mind and the methods of procedure which make for the 

 progress, and what are the types of mind and the methods of procedure 

 which make for the regress, of science. And I venture to think that 

 we may enquire also with profit, in some prominent instances, under 

 what circumstances in the past science has waxed or waned, as the case 

 may be, in its slow rise from the myths and mysticism of earlier eras 

 to the law and order of the present day. For it is a maxim of common 

 parlance, too well justified, alas ! by experience, that history repeats 

 itself ; or, to state the fact less gently, that the blunders and errors of 

 one age are repeated with little variation in the succeeding age. This 

 maxim is strikingly illustrated by the history of science, and it has been 

 especially deeply impressed upon us — burnt in, one might say — by the 

 scientific events of our own times. Have we not learned, however, 

 some lasting lessons in the hard school of experience, and may we not 

 transmit to our successors along with the established facts and principles 

 of science the almost equally well established ways and means for the 



